E-DRUG: Safety of Moxifloxacin for tuberculosis
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Reference is made to previous correspondence on E-drug on planned
clinical trials on moxifloxacin for TB (October 2005, how time flies!)
Friday last week the TB-alliance announced new studies on TB, including
one on moxifloxacin. See:
http://www.tballiance.org/newscenter/view-brief.php?id=726
In the press realease they write:
About Moxifloxacin
Moxifloxacin is a member of the fluoroquinolone class of antibiotics. It
has already been approved for other indications, including acute
respiratory infections, and is the first drug in the TB Alliance
portfolio to enter a pivotal registration trial. Moxifloxacin has a
different mechanism of action from those of current first-line TB drugs
and has demonstrated activity against Mycobacterium tuberculosis (M.tb),
the bacillus that causes TB, in both in vitro and in vivo studies.
Unlike some existing TB drugs, moxifloxacin does not interact with
enzymes that are involved in the body's handling of antiretroviral
therapies used to treat HIV patients.
Moxifloxacin has an excellent safety record, having been used in more
than 76 million patients in more than 140 countries. If clinical
development is successful, the TB Alliance and Bayer are committed to
making moxifloxacin affordable and available for TB patients where it is
needed most, especially in developing regions.
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On the same day, the Pharmacovigilance Expert Advisory Group of the UK
regulatory authority (MHRA, www.mhra.gov.uk) publishes minutes from
their 10 October meeting with the following info:
'Safety of moxifloxacin-an antibiotic
The Group was informed about emerging evidence of a risk of liver
toxicity and other safety concerns for an antibiotic called moxifloxacin
that is used to treat community acquired pneumonia, recurrent chronic
bronchitis, and sinusitis. The Group heard that prescribing information
for this antibiotic was recently updated with information about a risk
of adverse effects on the liver. The Group's advice was taken forward
for further regulatory discussion in Europe. The Group also advised that
in the meantime, a short article asking healthcare professionals to
remain vigilant for important side-effects associated with moxifloxacin
should be included in the November issue of Drug Safety Update (see
www.mhra.gov.uk/mhra/drugsafetyupdate)'. In this short notice they warn
of the risk of potentially fatal liver failure and toxic epidermal
necrolysis (a serious skin disease).
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There are also, as mentioned previously, other serious ADRs associated
with fluoroquinolones, the antibiotic class of which moxifloxacin is a
member. One wonders where TB-alliance get their information from or if
they let Bayer write the text. I am also sceptical to the number of
patients and countries where moxifloxacin is said to have been widely
used, but I do not know where to look for confirmation of the figures.
According to the international dictionary Index Nominum it is registered
in about 70 countries. We know that most countries in the world have a
poor pharmacovigilance system. Although serious ADRs are rare, there are
important risk groups and it cannot be stated that moxifloxacin has an
excellent safety profile.
regards
Ms Kirsten Myhr, MScPharm, MPH
Head
RELIS Drug Info and Pharmacovigilance Centre
Ulleval University Hospital
0407 OSLO, Norway
Tel: +47 23 01 64 11
kirsten.myhr@relis.ulleval.no
myhr@online.no